Rare earth metals draw attention

The elements required in many technologies face a supply crunch as China - the world's main producer - cuts back exports

Among the hottest commodities these days are the rare earth elements - obscure metals used widely in key technologies such as smart phones, televisions, hybrid cars, lasers and military equipment.

These elements aren't actually rare, or earths, for that matter. They are metals that are found readily on Earth's crust, but not in concentrations that make them easy to mine.

Geopolitical trade issues have shone a light on them in recent months. More than 90 per cent of rare earths are produced in China, and there are worries the country will cut back exports to ensure it has enough domestic supply, leaving technology producers in Japan and the West in the lurch. Those concerns were heightened last month when it was reported that Chinese rare earth exports to Japan might be trimmed after a diplomatic incident in which the captain of a Chinese trawler was detained by the Japanese in disputed waters.

Worries about the security of supply has boosted the prices of rare earth metals, and lit a fire under producing companies or those exploring for new mines. But the possibility of an investment "bubble" is itself a concern, as some institutional investors are retreating from the sector.

It takes years to get a new mine up and running, so even if the flurry of activity results in new production in the West, there could still be short-term shortages.

What they are

Of the 17 most commonly used rare earth metals, 14 appear on one of the lower rows on the periodic table - the part you probably paid no attention to in high-school chemistry class.

Many have unpronounceable names, such as dysprosium, praseodymium, ytterbium, and neodymium.

In combination with other elements, they form compounds that are highly useful as pigments for glass and ceramics, or as components in electronic products that require high heat resistance.